Wired broadcast distributing system



Aug. 2, 1932. E. E. CLEMENT 1,869,356

.WIRED BROADCAST DISTRIBUTING SYSTEM Filed Nov. 27, 1926 6 Sheets-.Sheet l 104 102 2.72 l; /l FW Y FX FX F2 g 8a Aug. 2, 1932. E. E. CLEMENT WIRED BROADCAST DISTRIBUTING SYSTEM Filed Nov. 27, 1926 6 Sheets-Sheet 2 ,nv O .m 6 s f 2 W no@ t 4 I 1U m W, w a f l on. Q f IIIIII lI/ll |II||I| Illl||l||l |l.|ll IIIII ...I J e f P en 2;/ l r y l 6 u s Y HV W v, EE0 E W2 oo m mwah w mmwmz uw Wm s n F 6 2 c, a 5H., m T, y iwfmi m .m m n al1 en. e em www@ ulwmz. I an. sal E I 00E 0 0F F M m d c n 0"2 r v f E m n ...n.w.. WMMC H H n CTM n u www main. P lm w ZW., i E m m n u I I l I IIJ* 1/4 ull. l l I l E m Il Il lllvlllllL l lllllll Il. n M l n nr 2 n 9 1, m A.V HM I 2 rf I ...L Mx. l llllll Il. lllll w. f A @M All@ 2 1.932 E. E. CLEMENT 1,869,356

WIRED BROADCAST DISTRIBUTING SYSTEM '@@uaz ma@ am@ 6 Sheets-Sheet 5 Aug. 2, 1932. E. E. CLEMENT WIRED BROADCAST DI'STRIBUTING SYSTEM Filed Nov. 27, 192e Patented A ug. 2, 1932 f U-NTD STATES PATENT 0F EDWARD E. CLEMENT, or WASHINGTON, DISTRICT or COLUMBIA, AssIeNoR To RDWAIgn F. CoLnADAY, oF WASHINGTON, DISTRICT or coLUrrRrA `f v WIRRD BROADCAST D ISTRIBUTING s YsTmr Application. led November 27, 1926. .Serial No. 151,116.

led October 28, 1924, foran organized sys- 5 l.tem ,of radio broadcast' distribution.4 The prescnth invention pertains especially to broadcastdistr'ibution overwires or wire net-v works by carrier currentand in general par allels` wired distribution the radio dis- ,iortribution method andrsystem of the earlier application, and provides further develop-` mentsvrelating top wired broadcast distribulgIt hasgfor itsL objects to provide predeterm mined selective distribution through and to different points; 'overI conductors common to several paths or lroutes of distributionyto provide predetermined distribution with selection at thereceivingfpoint, to provideA distribution ofgthe saine signals :to different geographical vtime divisions at diiferent periods of ultimate time.,to compensate for differences in geographicaln time, to provide `broadcast ffdistribution to subscribers .in 2: groups connected to the same or different `wire networks through diierent subscribers Service,stationsindividual to a group and to utilize the wire networks and trunking connectionsof existin wired electrical Vdis- 3 )tributin Isjystemsan g, communication systems.- ther objects of the inventionwill be ap arentfroni a perusal of ythe following fio @dividing lines. The primary or.master. s ta.f.

. tion for the whole system is designatedftlieo.,

i stationwhich is indicated at Ain the easternl g5 g speci cation and the drawings accompanyingthegamep,` C. 23,-; E1n the drawingspm Fig. 1 isadiagram of an area such as that of theUnited -States divided intoclock time divisions. showing'- the distribution of the different classes of Stationsand their physical 4 1; or trunking.connectionsg .Fig. .isamore detailed diagram of ,one o f .t h e fmain branches o f. the distribution channelsiand Sub-branches thereof between the. mainstation )and ,a subscribers station.

Iflig. 1, is a showing a ment for effecting selective distribution or.

routing by use of different sending quencies. Fig. 6 lis a diagram showngthe .master B stations or time division stations c0`11nectd.55

with hamster 0r Primary station''. th'rlfiv` 4; individual trunks and the relapon-ofrt .mi suceeding Vorders of stations tp4 `111g tionsw Fig. 7 vis a diagram illustrating anarrange-- 65 ment for effecting redetermined distribiif tion or routing by orward freqiiencie's.;l

Fig. 8 illustrates a, modification of theai-, rangement of Fig. 7 in Awhich selectivedrisf tribution may 4be effected among difeife'nt,65, groups of subscribers on a common network.-

9 is a diagram illustrating theinethodf of istributing to subscribers (stations i through network. f 10 is a table or chart showin thetiinefA sche ule and orderof vrepetition o dijrentf. classes of items .throughout'the systeijri; ff In Fig. 1 is shown the order or'clasfsificaf.

tionl of the different relaying. and distribut; 'u

ingstations in stages .expanding outw'ardl ly from a primary or master stationi to the,l ultimate Areceiving stations of subscr'i b ar s The area throughout which the .s tati n's; arel,; distributed is 'here .shown Aas thatof theg United States with the divisions betwen'itsf time zones or sectionsindicpatedby.heavy time division. The next order offstati(irrs's,'are the B stations, indicated in thedrawingsgljy.

the letter B, and of which.therearefseveral in each time division.` Of the 'severalgstafg tions in a time division v one is` a leadingorg one head station for the divisionwhich is te`rrx i ed l the master B station. `.The master B Stations, for the eastern, central, mountainandfPaoifie time divisions are indicated at' r B1, and Bt respectively4 while the sub 1statiolrs .,95.;V are similarly designated with the additionlbzf; a subscript, for examplethe s ulo B stations, under. master station Ba'lare indicated'ir. B2", etc. A common or main trunk. line-,MT" connects all, the masterl B, Statigll 10D primary or A station. Each sub B station connects with this main trunk at its respective master B station, for example B12, or another sub B station between it and the master B station for example B42. The next order of stations are the local distributing or C stations, indicated at C2, C2, etc. which receive from the B stations and distribute to the ultimate receiving stations or subscribers stations D, indicated at D.

To afford selective distribution or routing of broadcast items from the A station to the diiierent time divisions, the B stations of the different time divisions are tuned to receive on different carrier current frequencies respectively. Thus the A station sends to the B2 stations on fre uency FX, to B3 stations on frequency F ,etc. i

For a more detailed disclosure of the connections and system of distribution from the B stations on to the subscribers station or Dv stations reference is to be had to Fig. 2 in which the connections from the master B sta-y tion B", C2 and its subscribers stations D (of Fig. 1) are elaborated. In Fig. 2, the portion above the bracket marked B3 is situated at the B station B3 while that above the bracket marked C2 situated at the station C2 except the portion marked D which is a subscribers or D station.v rThe power station indicated atthe extreme right is a power station whose network is used as the transmission medium between the subscribe'rs local distributing lstation C2 and the subscribers stations D, and which power station may be located with or at a distance from the station C2. Y

Referring to Fig. 2 more in detail MT is the main or common trunk leading from the Astation through or past the station B3 onto the next B station B* or to a sub B station such as B23, (Fig. 1). To compensate for or off-set attenuation in the main trunk or branches thereof, band repeaters may be inserted as indicated by the rectangle labeled Band Rep. situated, preferabl at the master B stations. At the station l 2 the branch trunk 1, connects with the main trunk MT and extends this connection throughmultiple taps2, 3, etc. to the input side of carrier current frequency filters 6, 7, etc. tuned to pass one only of the four frequencies assigned vto the four master B stations which frequencies are designated FW, FX, and FZ for the stations B1, B2, B3 and B4 respectively. Normally each B station takes from the main trunk only the frequency assigned to it.` For example at station B3 (Fig. 2) onlyythe lfilter 8 for frequency FY is con,- nected through its sclosed switch 12 to the branch 1 leading from the main trunk MT, the remaining filters lbeing disconnected therefrom at their open switches 10, 11 and 13. While this is the normal situation, especially where all the BA stations arel connected to the A station through a common trunk, any of the other filters may be switched onto the trunk to take one or more of the items on the other frequencies FW, FX or FZ, where occasion requires. The use of several filters at the same time to take several items from the A station at the same time is the normal situation where separate trunks are used to connect the different master B stations with the A station, as shown in Fig. 6, a modification to be later described in detail.

For each of the relay filters 6, 7, etc. there is a corresponding local transmitter 16, 17, 18 andp119 each comprising an oscillator, modulator and transmitting filter as diagrammatically indicated. The transmitters 16, 17, etc. are designed to transmit on the standard carrier current frequencies FW, FX, etc. so that whatever one or more of these frequencies are not being taken from the A station may be used for items originating at the master B station. The output circuits of the relay filters and the transmitters terminate in multiple jacks 14-15, 19-20, etc. which enable them to be connected in various combinations through plugs 33, 34, etc. and coupling amplifiers 41, 45, etc. to the distributing lines or tunks 49 and 50, leading to the C stat-ions C1 and C2 served by the station B3. The coupler amplifiers 41, 45, etc. may be of any known or other form of one wa ampliiier, as indicated by the arrows, pre erably of the usual audion tube type, so that when two trunks such as 49 and 50 are connected to the same source through these am lifiers there will be no cross connection etween the trunks.

At the C stations, for example C2, a set of filter couplers 52, 53, etc., and local transmitters 62, 63, etc., are provided for the different standard carrier current frequencies FW FX, etc., the relay filters being associated with the trunk 50 in the same manner as are those of the B station with its incoming trunk. The output circuits of the relay filters and transmitters terminate in jacks --61, 66--67, etc., through which they may be connected in various combinations through plugs 72, 73, etc. and coupling, oneway amplifiers 76, 77, etc. to the network 8O served by the subscribers distributing station C2, to which the ultimate receiving stations or subscribers stations D are connected.

This network is here shown as that of an electric power distributing circuit of a power station 81 but may be any other electrical network or one provided for the purpose. While the subscribers house circuit 82 is here shown directly connected through the lead in wires 88 to the main power line or network for the sake of clearness and simplicity of disclosure, it is to be understood that such connection may be and preferably is made through protective devices, transformer, house meter, etc. A n ordinary attachment 51 such of the frequencies plug 84 is used for connecting the subscribers receiving set R to the house circuit, the receiving set being preferably self contained asy indicated and including suitable protective devices such as blocking condensers and the like not shown in Fig. 2. As with the B station, the relay filter 54 for the frequency FY is the only one normally connected to the branchtrunk 51, so that the frequency FY assigned to its B station will be relayed onto its subscribers, the other relay lters being connected with the branch trunk 51 when occasion requires as for selectin from the trunk vX, FY, etc. as may be put on this trunk from the station B3 or from the A station through the station B3. Where one or more other C stations are served from the same trunk or distributing line 50, this trunk is extended preferably through a-band repeater to the nearest such station as'indicated at 85 where the trunk is shown as 'extending to a sub C station C12, which station is 4not shown in Fig. 2 but which it is to be understood is equipped similarly to the station C2 for serving a group of subscribers on another network. i Such of the standard frequencies FX, FY. etc.` as are not being used for distribution from the station B3 through C2 overthe network V80 may be'fused for transmitting over this network items originating at C2, one or more of the transmitters 62, 63,v etc. being used accord- ,ingl to the frequencies required. f

A.I Fig?) Ais shown a detailed diagram of the circuits and apparatus elements of the subscribers receiver R at a subscribers station D. This consists of a detector tube 86 having its filament grid, or input circuit connected to a pair of primary input busses 87-88'arranged to be connected to the primary winding of any one of a set of four tuned couplers 89 to 92, through a pair of contacts 93 to 96 of one of the push button switches 97 to 100, respectively, each of which connections includes agrid leak and grid oondenser'as indicated in the conventional manner at 101. Each ofthe secondary windings of the tuned couplers 89 etc. is arranged to. be-connected across the secondary input busses 102-103 upon closure of its respective push. button switch 97 etc. through the`ex.

treme right hand contact thereof, the left hand terminal of each secondary winding being permanently connected to the bus 102 while the right hand terminal is connected through the push button contact to the lower bus 103.' The tuned couplers 89 to.92 are tuned to pass the frequencies FW to FZ respectively.A While the connection of only one terminal of eachof the primary and 'sec` ondary windings of the coupler coils is shown as lbeing controlled through the switch contact, it' will be understood that the connection. of both terminals may be so controlled :byf the use Aof additional contacts in the push buttons where it is desired to eect complete disconnection from the common busses of coils not being used. The primar input busses 102-103 are connected through suitable blocking condensers 104-105 to the terminals of an ordinary electric light attachment plug 84 through the engagement of which with a socket 106 wired to the house circuit 82, the connection is extended to the house circuit.

At the extreme left of each push button switch 97, 98, etc. is a normally open contact like that indicated at 107 arranged upon closure to connect the filament battery bus 108, leading from the upper terminal of the filament battery A, to the filament bus 109 which connects with one terminal of the filament through a filament rheostat 110. Thus as the other terminal of the filament connects through conductor 111 with the lower terminal of the battery A, closure of any one of the push button switches will complete the filament circuit. The plate or output circuit of the tube 86 is completed throughthe jack 112 by connection of the plate element of the tube with the lower jack spring, the connection of the upper jack spring with the positive terminal of the plate battery B, and the connection of the negative terminal of the plate battery through conductor 108 with the filament. The plate or output circuit may be traced from the upper terminal of battery B, upperspring of jack 112, lower spring of jack 112, plate element of tube 86, filament of tube 86, conductor 109, extreme left hand contact such as 107 of whatever switch is closed, conductor 108 back to negative terminal of battery B. It is desirable that each time one of the push button switches 97 etc. is closed, it will so remain until another is closed whereupon it will automatically release or return to the open position, and that the last but-ton actuated may be restored at will so as to open all circuits. To this end use may be made of any known or other suitable form of a push button set of the type usedtuated to shift the lock plate to release -thelirst and lock itself in actuated position, the lock plate being mounted for lateral parallel movement and held normally in locking position by supporting springs 115. I

ln the operation of the system as shown in Figs. -1 to 3, assuming the main trunk MT to be supplied from the primary station A' with different programs or items on the stand-V ardfrequencies FW, FX, FY and FZ for the leo different time divisions, eastern, central, mountain, and Pacific respectively, the master B station B3 for the mountain time division picks up the item transmitted on the carrier frequency FY through the branch trunk 1 (Fig. 2) switch 12 and relay filter 8 from which it is distributed to one or both of the trunks 49 and 50 through the multiple jacks and 26, plugs 37 and 38 and amplifiers 43 and 47 respectively The Whole group of standard frequencies FZ, F Y, etc. is also passed onto the next succeeding master B station B4 and to other sub B stations in the same time division as B3 for example B13 l trunk leading to station C12.

" and B2s as indicated in Fig. 1. At the station B2 (Fig. 2) any of the other frequencies not being used for the item or items received by it from the main trunk MT may be used by it for originating matter to be distributed to its C stations. For example, the transmitters 16 and 17 may be connected through their jacks 19, 20, 23, 24, plugs 33, 34, 35, 36 and amplifiers 41, 42, 45, 46 to the trunks 49 and 50 leading to the stations C1 and C2 to put thereon two other items on the standard car,

rier frequencies FW and FX, the transmitters 16 and 17 being arranged to transmit on these frequencies respectively.

The three items now being sent over the trunk 50 on the frequencies FV, FX and FY, are passed on through the band repeater to a sub C station of station C2 as indicated Where the trunk 50 is shown connected through a band repeater to an extension At station C2 the carrier Waves of frequencies FW, FX and FY are taken oif the trunk 50 through extension 51 and relay filters for these frequencies, FV, FX and FY, the switches 56,

57 and 58 being closed for this purpose, and

the transmission extended through the jacks 60, 66, 68, plugs and amplifiers 72-76, T23-77, Tel-78 to the network 80. As the frequency FZ is not included in this group of relayed frequencies, the stationary C2 uses the remaining frequency FZ for originating a fourth item or program of items by use of the transmitter 65 which is also connected through jack 71, plug 7 5 and amplifier 79 to the network 80, over which all the different items on their respective frequencies are now distributed in common to the house circuits 82 of all the subscribers stations D by Way of the leading in conductors 83. At

" the subscribers station D (Figs. 2 and 3),

the lock plate 114. This completes the energizing circuit of the filament of the tube 86 by connecting the battery lead 108 to the bus 109, and connects the input circuit of the detector tube 86 to the primary input busses through the tuned filter coupler 89 tuned to the frequency FW. The connection of the primary winding of the coupler across the conductors 102-103 may be traced from upper primary input bus 102, primary of filter coupler 89, right hand contact of push button 97, to bus 103, while the connection of the secondary Winding to the input circuit of the tube may be traced from left hand terminal of filament, secondary input bus 87, secondary of coupler 89, middle contact 93 of push button 97, grid leak and condenser 101, and bus 88 to grid of tube 86. As the filter coupler 89 is tuned to pass only the frequency FW this frequency only is received and demodulated by the tube 86 and the modulations reproduced in the output circuit (previously traced) and rendered audible by any suitable type of receiver, not shown, connected in circuit through the jack 112. The receiver may be a simple telephone headset, but is preferably a loud speaker of the usual built-in type as indicated at 11G in Fi 2 with the necessary amplifying means o any known or other suitable form not shown. Should the subscriber desire to change to a different item he depresses the push button corresponding to the frequency on which that item is being transmitted which releases the push button '97 to disconnect the filter coupler 89, connects 'in the desired filter coupler and locks itself in actuated position, all in a manner similar' to that described in connection with push button 97. To disconnect his receiving set the subscriber silnply depresses the off button which shifts the locking plate 114 to the left to release Whatever button is latched down at the time and locks itself under the release plate. thus disconnecting all filter couplers 'and opening the circuit of the filament current su ply at the extreme left hand contacts.

Vhen desired, any of the relay stations may. broadcast by radio to enable .subscribers to receive therefrom directly by radio, or by Wire from a station which receives by radio from the Wire relay station. Also, wherever' desired, a subscribers local distributing station may takeoff the main trunk MT direct. These arrangements are indicated dia ram'- matically in Fig. 4, where A is the A sta-f tion or primary station, and MT the main distributing trunk distributing to the master B stations B1, B2, Bs and B4 each of which is shown with an antenna for radio broadcasting. D5 represents one of a group of subscribers stations which receive over a yWire net Work from a local distributing station C5 receiving by radio from one of thev master This opens all the contacts afi ' C2 serving different groups of subscribers D1 and D2. In the operation of this arrangement, the station B4 takes the carrier current of frequency FZ from the main trunk MT through the selective ampliier,tuned to pass only thev frequency FZ, and passes it onto the common trunk 'CT through switch 117 along with the output of one or both of its local transmitters 118 and 119 through switches 120 and 121 respectively, the transmitters 118 and 119 transmitting on frequencies c1 and c2 which are the special receiving frequencies of distributing station C1 and C2respectively. These three standard frequencies, FZ, o1 and c2 are thus put on the trunk CT common to both lC stations. The stations C1 and C2 now both pick off the frequency FZ, intended for both groups of subscribers, by means of their selective relays 122, 123 and distribute it to their subscribers over the networks 124 and 125,'respectively, while station C1 only picks .off frequency c1 and station C2 only picks oil frequency c2 through the special selective relays 126 and 127 respectively. The frequencies c2 and c2 are preferably two of the four standard frequencies other than FZ, for exam le FW and FXbut here designated c1 and c2 ecause of their being individual tothe stations C1 and C2 respectively. As this accounts for only two ofthe four standard frequencies forv each of the groups of subscribers D? and D2, each of the C stations 'may supply a third item on the frequency FY by means of local transmitters 128 and 129 respectively,and if de-Y sired a fourth item by means ofl another transmitter at each C station not shown,each arranged to transmit on the frequency special to the other station, this being made .possible by virtue ofthe separation of the networks 124 and 125. Thus each group of sub scribers vhas choice of any one of four items or progra-ms, one-of which may or may not be special to itsgroup according to the distribution determined at the station B4L which may send different special items to different C stations or vthe same special item to both. It will also be apparent that the matter received from the main trunk MT on fre'- uency-FZ may be made special to one of the stations by demodulation and retransmission on one of the special frequencies at station B. '1,

In F 1g. 6, 1s; shown a more complete view of the general lay-out of the stations especi- ,.70

however differs slightly from that previously t described in that `instead of all the master` B stations being connected with the primary or A station over a common channel, they are each connected with the primary station over individual trunks T2, T2, etc. `The operation of the vsystem as here shown is the same 'as that of the arrangements previously described except that the primary or Astation may transmit items directly to anyone Vof the master B stations on any onel or more of a number of frequencies, the master B stations, for example B2 (Fig. 2) passing them 0n through relay filters to their C .stations in a manner as previously described. To show the rotation of the stations previouslyv described in detail, to the general system as illustrated in Fig. 6, they are identified' thereon by the same reference numerals, for example (in Fig. 6) station B3, the station C2 connected thereto by trunk 50, one of the stations D connected to this station C2 .and the network connecting C2 with its stations D, are the same as the parts designated by the same reference characters in Figs. 1, 2, 3 and 5. Itis preferable to provide means for supervision of the subscribers stations D from their local 'C stations over individual line connections which may be either individual wire line connections from the local or 1C station to its D stations as indicated at-CTL (Fig. 6) or individual wire lines such as telephone lines TL adapted to be individually connected to the C stationthrough a telephone exchange TEL EX. and the'C station individual line CL as shown with re-l gard to station C under B2 in Fig. 6. *"2* Another arrangement for effecting selective distribution of which the system is capable is shown in the right hand portion of Fig. `6 applied to the arrangement and adjustments of the master station B1 and the C: and D stations thereunder. Here the general relation is the same as that previousl described except that the D stations un er each Cst'a-L tion are divided into two groups by alloti'nen'tY of different receivin frequencies, 'which gives four groups in a l to which the station B1 may selectively distribute by the use of different combinations of trunks CT1 and CT2'and the standard frequencies FX 'and FY. For example, the D stations under C2 are divided into groups D1 and D2 by virtue:y of their being tuned to Areceive lon` the standard frequencies FX .and FY, respectively, whilefthe D stationsy under C2 are divided into groups D3 and D4 by being Ituned to' reico ilo

iis

ian

ceive on the standard frequencies FX and FY respectively. Thus in operation, the stations C1 and C2 under B1 being set. to relay the modulated frequencies FX and FY sent them from the B station onto their respective subscribers networks, the station B1 may selectively distribute through its C stations to any one of the groups of subscribers by proper trunk and frequency. For example:

Frequency FX on trunk CT 1 selects group D1 Frequency FY on trunk CT1 selects group D2 Frequency FX on trunk CT2 selects group D3 Frequency FY on trunk CT2 selects group D* In Fig. 7 is shown an arrangement for effecting predetermined distribution or routing by forward frequencies re-routed at the different stages of relay7 stations. Here the B station for example B3 is arranged to receive items or programs over trunk T3 preferably by carrler current from the primary station, not shown, demodulate the same by the demodulator 130 from which the items may be retransmitted on any one or more of the different standard frequencies FlV, FX, FY and FZ through the modulator oscillators or transmitters 131 to 134 respectively, over a trunk 135 to the C station C1. At C1, the trunk 135 connects with a pair of filter band repeaters 136 and 137 tuned to pass only the frequencies FW--FX and FY-F Z onto trunks 138 and 139 respectively, leading to different sub C stations. The trunk 139 leads to sub C statiton C11 where it connects with a pair of filter repeaters 140 and 141 tuned to pass only the frequencies FY and FZ respectively, and aranged with their output currents connected to the lines 142, 143 and 144 as indicated. These stations, especially the stations C2 and C11 may conveniently be existing Wire distribution service stations such as tele hone or telegraph stations, and are here indlcated as telephone stations, station C1 being a main exchange and C11 a branch exchange. At C1 the line 138 may lead to another branch exchange like C11, or may be a telephone line having two or more party line stations with sets tuned for receiving on one of the standard frequencies FW or FX. At C11 the lines 142, 143 and 144 represent subscribers telephone lines. Y

From the above description, it will be clear that in operation, matter received at B3 over the trunk Ts may be routed to any one or more of the ultimate distributing lines 138, 144 or 142-143, or one or both of the two parties or sets of parties on line 138 by use of the proper relay transmitter or transmltter 131 to 134 at B1'. For example, if it is desired to distribute to the one or more parties on line 138 tuned to FX, the matter 1s relayed from B3 through transmitter 132, or if to both this set of arty line subscribers and the subscriber on line 144 then the mat- The arrangement illustrated in Fig. is V the same as that of Fig. 7 except that the station C11 instead of serving individual subscribers lines, serves a network 145 onto which it passes both frequencies FY and FZ, the subscribers stations D3 and D4L being connected in common to the network but divided into two groups by frequencies, the stations D3 being tuned to receive only on frequency FY and the stations D* only on frequency FZ. The operation of the system of Fig. 8 is the same as that of Fig. 7 except that when transmitters 133 and 134 are used at station B3, the matter is routed to one' or both of the two large groups of stations on the network 145 according as to whether one or both of these transmitters are operated. By varying the connections or the tuning of the different filters at the different stations, the routing may be varied to suit different requirements. 1 g A In Fig. 9, is shown an arrangement of the B, C and D stations for selective distribution through a C station to D stations on forward frequencies over a common medium, here shown as a common wire network. Here the relation of the primary or A staV tion and the master B stations are the same as that of Figs. 1 and 2. From the master B stations on down to the D stations, the gresentvarrangement differs from that of igs. 1 and 2 in that the master B station, for example, B1, is connected with its C stations C1 and C2 over the same common network 146 to which the D stations are con nected. Here the arrows marked b, c and d represent the receiving frequencies of the stations B, C and D, respectively, and their direction of distribution, it being remembered of course that the carriercurrents are not unidirectional, the arrows being used'Y simply to show direction of distribution ,or routing only. Station B1 is tuned to receiveI from the primary station on frequencyb and retransmit over the network 146 on fre-4 quency 0 while station C1 receives from the network on frequency o and transmits over the same network on frequency d to which the subscribers stations D2 are tuned 'for reception from the same common' network. Other C stations and their D stations such as C2 and its D stations D2 are also connected to the same common network 146 but tuned to a differentset offrequencies. Thus, in operation, when B1 transmits on frequency ter is relayed through both transmitters 132: 0 over the network, the'signals will be `distributed through Ci to its D stat-ions D1, to the exclusion of stations C2 and D2 on the same common network. Similarly, the same represents a telephone exchange central office having access to the several B, C and D sta- Vtions through individual wires such as 147 and 148 indicated in dotted lines. Through =these co-nnections Ithe C station may have access to the D stations for supervision, pick up of items to be broadcasted, etc. Itis also possible for the station C2 to pick up from one of the'stations D2 by the use of a portable wire transmitter at'the particular D2 station arranged to transmit on the frequency c to which at C2 is tuned.

In Fig. 10, is shown a vscheme of distribution in which the four time divisions of the country are served with overlapping repetif' tions of the same program which may be made up of national items exclusively. The four vdivisions are 'allotted receiving frequencies F'W, FX, FY and FZ but the maximum number of frequencies required at any one time is three, and when all four divisions are receiving, only two frequencies are required for the stated program. The value of this arrangement lies in the fact that two frequencies and at the same time three out of the four are available for specials which may originate at A, B or C stations. It will be observed that frequency FW for division 1 carries the program straight through from 6 p. m. to midnight, from item 1 to item 18 inclusive, in regular numerical order. Frequency FX intended for division 2 commences an hour later and carries the same program straight through if desired, but preferably does not carry items 7 to 15 inclusive because those items can be obtained during the same period from frequency FX for specials, or saving it entirely. Frequency FY commences an hour later than FX and can also carry straight through but preferably has items 4 to 12 inclusive omitted for the same reasons as before stated with respect to FX. Frequency FZ commences an hour later than FY, and carries straight through the entire program. In order that divisions 2 and 3 may be able to receive all national program items, their. receivers are tunable to frequencies FW and FZ as well as their own. Division 2 would rst receive on frequency FX the first six items, then tune to frequency FW for items 10 to 15 inclusive, then tune to FZ for items 7, 8 and 9, and finally tune back to its own frequency for the last three items in the program. To indicate this routing on selection by means of frequencies, I have shown dotted'lines indicating the items and the frequencies received in divisions 2 and 3 according to this method.

the receiving apparatus -station, a district distributing "station,

The exes shown in the figure indicate that the'particular frequency opposite which they appear does not carry the items under which they stand but is. blank and available for specials or the like. Of course, the hours, the number of items, and other conditions are arbitrarily assumed and may be varied without departing from the invention.V Attention is also called to the fact that while I speak of tuning, it is not essential to have tunable instruments or to actually change the tuning during receiving, as each division may 4have a plurality of receivers ixedly. tuned which can be switched in when required or; left in and the relay circuits switched to one or another as required.` i

What I claim'is:

1. In an organized wired broadcasting system, a plurality of subscribers stations 1 divided into local groups, a centralized loca-l distributing station for each group, la wired network connecting said subscribers stations and their respective local distributing -stations, wired broadcast receiving means at;-h4

each subscribers station connected with its associated local station for supervision therefrom, a district service station connected to a group of said local distributing stations over a common wire connection, wired broadcast receiving means at each local distributing station the receiving sets of different local distributing stations being tuned to different wave lengths different for different stations, means at said local distributing stations for relaying' signals received on their receiving sets to their respective subscribers over the connecting network, and means at .the district station for transmitting the same ico or different signals over said common kwire connections on the said different wave len hs "to which the receivers of said local distri uting stations are tuned whereby the local distributing'stations and their lgroups of subscribers are segregated by wave lengths independentlyof physical connections. e

In an organized wir'ed'broad'cast system, a plurality of wired networks each having a plurality of subscribers stations con- Anccted thereto in common, the subscribers on 'a common network being divided into groups by tuning, carrier current receivin means lat each subscribers station connecte for reception from 1ts network, the receivm sets of the different groups on a network eing tuned to different given wave lengths diii'erent for different groups, a local distributing p 4 o said local distributing stations being eachucon- 'nectedvto one of said different wired networks, lwire connection between said district 1distributing station and all said local distributing stations, means at said district istation for transmitting signals to the local distributing stations on said different given wavelengths, and means at the local stations l"fao iso for relaying certain of said wave lengths onto the diierent networks whereby a signal may be routed from said district station to any group of subscribers on any of said networks.

3. An organized system of wire communication having subscribers stations distributed over a wide area, local exchange stations serving said subscribers in local aggregated groups, said local exchange stations each connected to its subscribers by individual wire circuits, and all said local exchange stations interconnected over the general area by Wired trunk circuits, in combination with subscribers carrier current receiving stations distributed over the same area arranged in groups, each group connected to receive from a loca-l network and connected with the same subscribers line circuits, local central stations arranged to broadcast by carrier current on said networks and containing terminals of said lines, and also terminals of said wired trunk lines, and an organized system of carrier current relaying comprising graduated stages of relay stations arranged to cover the general area, one stage being the local stations distributing direct to the subscribers by carrier current over the local networks on xed wave lengths, and supervising the subscribers receiving over their individual wire circuits, the next being an intermediate stage receiving over a trunk on a fixed Wave frequency and distributing to the local stations over a trunk on a second fixed wave frequency, and so on to a master station broadcasting for the time being, over a trunk to one or more relay stations on carrier currents of different frequency.

4. An organized system of carrier current broadcast distribution, comprising a large number of subscribers divided into groups with a common network for each group from local distributing central stations, wire connections other than said networks from each of said local central stations to its subscribers, means at the local central stations for broadcasting by carrier current on a iiXed carrier wave frequency to subscribers in their respective networks, and a plurality of sets or stages of radio relay stations each set or stage receiving on the same carrier wave length and relaying the modulation on a different carrier wave length xed for any particular station of the stage next below it.

5. In an organized Wired signal system having a plurality of subscribers stations divided into groups with a subscribers distributing service station for each group, a common wire network connecting each Agroup and its service station, carrier current receiving means at each subscribers station having its input circuit means connecting it to said network and connected with its associated service station for supervision therefrom, trunk lines connected to said service stations, and means for transmitting different classes of matter over different trunks to the different service stations to effect differential distribution among said different groups of subscribers.

6. In a system of broadcasting, a wire cir cuit, means for transmitting signal modulated carrier currents over said circuit, a relay station containing an amplifying relay selective for one of said currents, local distributing stations connected to said relay station by a wire circuit, each containing a selective amplifier and relay for said carrier current, and subscribers stations connected to each of said distributing stations, each of said distributing stations having a second amplifying relay selective for a second carrier current frequency allotted to it, and means at the relay station to distribute signals to said distributing stations by sending to one or the other over the common circuit each on its own allotted frequency.

In testimony whereof I hereunto aix my signature.

EDWARD E. CLEMENT. 

